package com.css.common.core.utils.sign;

import java.security.MessageDigest;

public class MD5Utils {

    public static final String CHARSET_DEFAULT = "UTF-8";

    private MD5Utils() {
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            resultSb.append(byteToHexString(b[i]));
        }

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String encode(byte[] bytearray) {
        String resultString = null;
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            resultString = byteArrayToHexString(md.digest(bytearray));
        } catch (Exception exception) {
        }
        return resultString;
    }

    public static String encode(String origin) {
        return encode(origin, CHARSET_DEFAULT);
    }

    public static String encode(String origin, String charset) {
        String resultString = null;
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charset == null || "".equals(charset)) {
                resultString = byteArrayToHexString(md.digest(origin.getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(origin.getBytes(charset)));
            }
        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
            "e", "f"};
}
